1. Technical Field
The present invention relates to a technology for performing a gray scale in such a manner that one field is divided into a plurality of sub-fields and pixels are caused to enter an on state or an off state in each sub-field.
2. Related Art
When the grayshade is performed in an electro-optical device that uses display elements, such as liquid crystal capacitors, in pixels, the following technology has been suggested as a substitute for a voltage modulation method. That is, there has been suggested a technology for performing halftone display in such a manner that one field is divided into a plurality of sub-fields and then the pixels (liquid crystal capacitors) are caused to enter an on state or an off state in each divided sub-field to thereby change the percentage of a time period during which the pixels are caused to enter an on state or an off state within the one field, which is described in JP-A-2003-114661. On the other hand, each liquid crystal capacitor is configured so that a liquid crystal is held between a common electrode and a pixel electrode. In order to suppress the voltage amplitude of a data line (source line), it has been suggested that the common electrode is alternately switched between a low-level voltage and a high-level voltage, which is described in JP-A-62-49399.
However, in a case where driving is performed in such a manner that one field is divided into a plurality of sub-fields, when a technology for alternately switching the voltage of the common electrode is employed, there occurs a problem such as a deterioration in contrast ratio or a decrease in the number of addressable gray-scale levels. An advantage of some aspects of the invention is that it provides a technology, or the like, for improving a deterioration in contrast ratio or a decrease in the number of addressable gray-scale levels when driving is performed in such a manner that one field is divided into a plurality of sub-fields and the voltage of the common electrode is alternately switched.